If this does not helps... This is more of a question for OS X Mavericks forum like: https://discussions.apple.com/community/mac_os/os_x_mavericks?view=discussions
You know this is general OS X question: How to open a specific file type (in your case DOCS) by specific application (in your case LibreOffice). You have to instruct OS X to choose LibreOffice for some specific file types... so much more OS X question then LibreOffice question.